Upper Coedcae: Petrol in a Diesel Car? How Worried to Be
Less than you likely are, if it has not been started. Everyone around Upper Coedcae begins with "have I ruined it?", and the fair answer is normally no: petrol resting inside that tank of any diesel stays harmless until priming, cranking or driving draws it into the system. To leave the car like that, ring Petrol in Diesel and leave the motor alone. The rest of this page covers what petrol really does to a diesel, how to tell how far it has got, and how to make sure it doesn't happen to you again.
What petrol in a diesel does to your engine
On its way through a motor, diesel has two jobs. Oiling comes before burning; it does both. Made to extremely fine tolerances, the injectors and the pump depend on the diesel flowing through them to stop their surfaces wearing against one another.
The second job petrol doesn't do at all, and the first it does poorly. The rattling comes from petrol being designed not to ignite when compressed, which is precisely the reverse of what a diesel needs. On top of that it is thinner than diesel, it strips away the protection the system hinges on, and any pump working on such a mix is wearing itself.
Put those together and the shape of the problem is clear. Contact doesn't do the damage — movement does. Any tank with petrol in it is a fuel problem. A pump that has been working on that petrol is the beginning of a mechanical one, and whatever a worn pump sheds travels on with your fuel to the fuel injectors further on.
Four scenarios our engineers see around Upper Coedcae: how serious is petrol in a diesel?
Filled up, never started. The best case there can be. That petrol is inside the tank and just that tank, and the task is a drain and a flush where the vehicle sits. This is the one scenario that can only really take place on a forecourt, as anywhere else your car has been driven to get there.
A moment's running, or merely your ignition on. Once primed, the system has drawn petrol from your tank up to your filter and the lines. Drain, flush, deal with your filter: still normally simple.
Driven a few miles. Now your pump has spent these miles labouring on thinned fuel. Distance is only half of it; how hard it was driven matters equally. Either way this work runs to your tank, your lines, the fuel filter and fresh fuel through the entire system. Short trips, like the school run to the local primary school, are one matter. Very different once more: a trip to Newport, under 15 miles away, or any miles on the M4, under 15 miles from Upper Coedcae, where your engine kept labouring hard.
Clattering, a lumpy idle, smoke, a throttle gone soft: driven till it complained. What you are hearing is the motor signalling fuel that no longer behaves like diesel. Pull up wherever you are — the verge on Coed Llwyd Close, a lay-by, a side street — and leave the car there. Permanent damage is very uncommon when a car is stopped quickly, and the drain and flush that still go first take care of it.
What Upper Coedcae people get told about petrol in a diesel — and the myths in it
Myth: "Fill it the rest of the way with diesel and it will be fine." It will not. Nothing comes out when you top up — your tank just holds more of the same mixture. That advice supposes a diesel fuel system handles petrol by percentage. It does not.
If anything, the opposite holds. Myth: "A modern diesel can cope with a bit of petrol." Protection matters more on newer diesels, not less, because their fuel runs through finer parts at higher pressure.
Myth: "If it starts and drives, there is no damage done." This is the one that fools motorists. Any petrol motor fed diesel generally will not run, and so the motorist stops and the harm stops with them. Nothing seems to have happened when a diesel fed petrol fires up, ticks over and drives away, which it usually will; meanwhile the pump grinds. Running does not mean fine.
Myth: "Add some two-stroke oil and drive it home." It's an old fix for a distinct fault. The petrol is still inside the tank afterwards, and what it has thinned isn't put back.
Myth: "Drain the tank yourself and you are sorted." Once the engine has been run, some of the petrol is no longer inside that tank: it is in the filter and your lines, and it goes right back through the pump at your next start. Emptying petrol into a can by the roadside is also really dangerous.
How does petrol in a diesel happen?
No one does it on purpose, and it's rarely carelessness. The forecourt makes it easy: the petrol nozzle is the smaller of the two, and it slides into a diesel filler with almost no resistance, while a diesel nozzle mostly will not go into a petrol motor at all. So the error runs one way.
When habit and the vehicle stop matching, it occurs. A vehicle that is new to you — a hire car, on loan as a courtesy car, or just bought. A household with one petrol and one diesel on the driveway. The pumps in a different order on a familiar forecourt. Fuelling up in a rush on the way to Abergavenny, with a train to catch. Years of petrol cars behind you, a diesel Volkswagen Tiguan in front of you at the forecourt for its first tank — that is when. Add a back seat full of children, a phone call or rain, and the hand wins.
Avoiding petrol in a diesel next time you fill up in Upper Coedcae
- Read the petrol pump, not the colour. In the UK unleaded handles are generally green and diesel black, yet not on each forecourt. The label is what counts.
- The first fill in a strange motor is the time to check your filler flap — on it, or on the cap, plenty of vehicles state the fuel to use.
- Mark your key. In a home with one of each, a coloured fob or a sticker on your diesel's key does more than any amount of meaning to remember.
- Before the nozzle comes off the pump the first time you fill a hired or new vehicle, say "diesel" aloud. Daft, yes, yet it works.
- Mistakes like this are straightforward to make while your mind is on something else, so the phone goes away.
- Up to a point, a misfuel inhibitor helps: some diesels have a filler built to block a petrol nozzle, and add-on devices are available for the rest. Treat it as a backstop, and keep reading the petrol pump.
- The moment you notice, stop: less petrol inside that tank means a thinner blend. What to do next doesn't change, though — still don't start it.
Upper Coedcae: already put petrol in a diesel?
The order of things is short, then. Leave it unstarted, with your ignition off as well. The staff at the forecourt — whether at Shell itself or wherever you filled up — will normally help push it away from the petrol pump if you ask. Then phone 0333 366 0103 and tell us what was put in, roughly how much, and whether it has run.
Corrosion and deposits are the trouble with AdBlue, whereas petrol means lost lubrication. So if it was AdBlue, say so — and read its own Upper Coedcae page.
One petrol in a diesel task in Upper Coedcae costs more than another. Why?
There's no fair single quote for this, because the four situations above are four different tasks. Which of them you're in is chiefly what shifts your cost. After that it's the ratio — how much petrol was put in against how much the tank takes — and after that where your car is and whether a van can reach it safely.
Before any quote, not after, come three questions: the fuel that got in, the volume, and if it's run. That's why. A range turns into a straight figure once those answers are in.
About Upper Coedcae itself
Upper Coedcae is a suburban area situated on the riverside in Torfaen, with a mix of terraced housing and a relatively high elevation of 384 metres. Upper Coedcae lies near the communities of Middle Coedcae and Blaenavon, and is connected to the city of Newport, which is approximately 13 miles away. Upper Coedcae has a population of around 3605 people, and its location reflects the blend of industrial and natural heritage found in this part of Wales.
Fuel drain cover around Upper Coedcae and across Torfaen
Middle Coedcae, Blaenavon and Rifle Green are among the locations around Upper Coedcae that the same vans work, answering petrol in diesel call-outs across Upper Coedcae's NP postcode area. You need not move the vehicle to us. Forecourts, supermarket car parks, lay-bys and your own drive are all places where we work.
In Upper Coedcae and still at the petrol pump?
In that case, you couldn't be in a better place. Keep it off. Phone.